Method for optimizing the optical power in an optical network and an optical network

Abstract

The invention relates to a method for optimizing the optical power in an optical network that has a plurality of network nodes each having a transmitter and a receiver. The method comprising generating an optical signal at a first network node, receiving the optical signal at a second network node, detecting the optical power of the optical signal at the second network node, determining whether the optical power detected is outside a defined range, and in this case, generating, for the first network node, a control signal for increasing or decreasing the optical power, sending the control signal to the first network node, and increasing or decreasing the optical power of the optical signal emitted at the first network node. The invention further relates to an optical network having network nodes which are operable to implement this method.

1. A method for optimizing the optical power in an optical network that has a plurality of network nodes each having a transmitter and a receiver, comprising:
 generating an optical signal at a first network node; 
 receiving the optical signal at a second network node; 
 detecting the optical power of the optical signal at the second network node, wherein during a regulating operation a determination is made in a second network node whether the optical power detected is outside a defined range; 
 if it is determined that the optical power is outside the defined range, generating, for the first network node, a control signal for increasing or decreasing the optical power; 
 integrating the control signal in a predetermined region of a frame, the frame comprising at least one additional region containing synchronous data and at least one additional region containing asynchronous data; 
 sending the control signal within the frame to the first network node, wherein a receiver of the second network node is used to convert the optical signal at the second network node into an electrical signal; 
 if the optical power detected is outside of the defined range, an electronic module adds the control signal to the electrical signal; 
 the electrical signal is supplied to a transmitter of the second network node and converted into an optical signal for transmission to the first network node; and 
 increasing or decreasing the optical power of the optical signal emitted at the first network node in response to the control signal until the optical power detected at the second network node is within the defined range. 
 
   
   
     2. The method of  claim 1 , wherein integrating the control signal in a predetermined region of a frame further comprises generating frame level error correction information and control data level error correction information. 
   
   
     3. The method of  claim 1 , wherein the control signal is transmitted to the first network node via the optical network. 
   
   
     4. The method of  claim 3 , wherein signal transmission in the optical network is subject to a transmission protocol that defines at least one user channel for transmitting the synchronous and asynchronous data and at least one control channel for transmitting control and signaling data, the control signal in the control channel being transmitted to the first network node. 
   
   
     5. The method of  claim 1 , wherein the optical power levels detected at the individual receivers of the network nodes are stored in a memory. 
   
   
     6. The method of  claim 1 , wherein a control signal is generated irrespective of whether the signals received at the second network node are intended for the second network node or are forwarded to another network node. 
   
   
     7. The method of  claim 1 , wherein detecting the optical power of the optical signal at the second network node comprises:
 using a photodiode to convert the optical signal into an electrical signal; and 
 determining the optical power received by measuring the photodiode current. 
 
   
   
     8. The method of  claim 1 , wherein the optical network comprises a serial network in which optical signals are transmitted between adjacent network nodes. 
   
   
     9. The method of  claim 1 , wherein the optical network comprises a ring topology. 
   
   
     10. The method of  claim 1 , wherein the optical network comprises a unidirectional network. 
   
   
     11. The method of  claim 1 , wherein the control signal generated by the second network node contains the address of the first network node in the optical network. 
   
   
     12. The method of  claim 11 , wherein the address of that network node which precedes the second network node in a unidirectional optical network is given as the address of the first network node. 
   
   
     13. The method of  claim 1 , wherein the first network node increases or decreases the optical power by a defined amount after it has received the control signal. 
   
   
     14. The method of  claim 1 , wherein the attenuation of the individual transmission paths of the network is determined from the optical power levels instantaneously detected at the individual receivers of the network nodes. 
   
   
     15. The method of  claim 14 , wherein the attenuation of the individual transmission paths of the network is evaluated for network diagnosis. 
   
   
     16. An optical network that has a plurality of network nodes each having a transmitter and a receiver, wherein at least one of the network nodes comprises:
 means for detecting the optical power of an optical signal that was emitted by another network node; 
 means for determining whether the optical power detected is outside a defined range; 
 means for generating, for that network node which emitted the optical signal, a control signal for increasing or decreasing the optical power if the optical power detected is outside the defined range, the means for generating configured to integrate the control signal in a predetermined region of a frame, the frame comprising at least one additional region containing synchronous data and at least one additional region containing asynchronous data; and 
 means for sending the control signal to that network node which emitted the optical signal; and wherein at least a further one of the network nodes has means for increasing or decreasing the optical power of the emitted optical signal as a function of the control signal for increasing or decreasing the optical power, the means for sending adding the control signal to an electrical signal, the means for sending further converting the electrical signal into an optical signal. 
 
   
   
     17. The optical network of  claim 16 , wherein provision is made of a central memory that stores one or more of the optical power levels detected at the individual network nodes and one or more values derived therefrom. 
   
   
     18. The optical network of  claim 16 , wherein the means for generating a control signal passes the control signal to a control channel of the optical network, the control signal being transmitted to the emitting network node via the control channel. 
   
   
     19. The optical network of  claim 16 , wherein the optical network is a serial optical network. 
   
   
     20. The optical network of  claim 16 , wherein the optical network has a ring topology. 
   
   
     21. The optical network of  claim 16 , wherein the network is a unidirectional network. 
   
   
     22. The optical network of  claim 16 , wherein the means for generating further comprises generating frame level error correction information and control data level error correction information. 
   
   
     23. The optical network of  claim 16 , wherein an address of a preceding network node in a unidirectional network is given as the network address of the emitting network node. 
   
   
     24. An optical network that has a plurality of network nodes each having a transmitter and a receiver, wherein at least one of the network nodes comprises:
 an electronic module configured to detect the optical power of an optical signal that was emitted by another network node; 
 a power analyzer configured to determine whether the optical power detected is outside a defined range; 
 a controller configured to generate, for that network node which emitted the optical signal, a control signal for increasing or decreasing the optical power if the optical power detected is outside the defined range, the controller configured to add the control signal to the electrical signal such that the control signal is arranged in a predetermined region of a frame, the frame comprising at least one additional region containing synchronous data and at least one additional region containing asynchronous data; and 
 a control medium configured to send the control signal to that network node which emitted the optical signal; and wherein at least a further one of the network nodes comprises a microcontroller configured to increase or decrease the optical power of the emitted optical signal as a function of the control signal for increasing or decreasing the optical power. 
 
   
   
     25. The optical network of  claim 24 , wherein the controller is further configured to generate frame level error correction information and control data level error correction information. 
   
   
     26. The optical network of  claim 24 , wherein the controller is further configured to pass the control signal to a control channel of the optical network, the control signal being transmitted to the emitting network node via the control channel. 
   
   
     27. The optical network of  claim 24 , wherein the optical network comprises a serial optical network or comprises a ring topology. 
   
   
     28. The optical network of  claim 24 , wherein the network comprises a unidirectional network. 
   
   
     29. The optical network of  claim 24 , wherein the controller is further configured to add the network address of the emitting network node to the control signal. 
   
   
     30. The optical network of  claim 29 , wherein the address of the preceding network node in a unidirectional network is given as the network address of the emitting network node. 
   
   
     31. The optical network of  claim 24 , further comprising a central memory configured to store one or more of the optical power levels detected at the individual network nodes and one or more values derived therefrom.